<template>
  <div class="header">
<!--    折叠图片-->
    <div class="collapse-btn" @click="collapseChange">
      <i class="el-icon-menu"></i>
    </div>
    <div class="logo">鲸智图书后台管理</div>
    <div class="header-right">
<!--      全屏功能-->
      <div class="btn-fullscreen" @click="handleFullscreen">
        <el-tooltip :content="fullscreen?`取消全屏`:`全屏`">
          <i class="el-icon-rank"></i>
        </el-tooltip>
      </div>
<!--      头像-->
      <div class="user-avator">
        <img src="../assets/img/user.jpg" alt="">
      </div>
      <el-dropdown class="user-name" trigger="click" @command="handleCommand">
        <span class="el-dropdown-link">
          {{userName}}
          <i class="el-icon-caret-bottom"></i>
        </span>
        <el-dropdown-menu slot="dropdown">
          <el-dropdown-item command="logout">退出登入</el-dropdown-item>
        </el-dropdown-menu>
      </el-dropdown>
    </div>
  </div>
</template>

<script>
  import bus from '../assets/js/bus'
  export default {
    name: "TheHeader",
    data(){
      return {
        collapse: false,
        fullscreen: false
      }
    },
    methods: {
      collapseChange(){
        this.collapse=!this.collapse
        bus.$emit('collapse',this.collapse)
      },
      handleFullscreen(){
        if (this.fullscreen){
          if(document.exitFullscreen){
            document.exitFullscreen()
          }
        }else{
          let element=document.documentElement;
          if (element.requestFullscreen){
            element.requestFullscreen()
          }
        }
        this.fullscreen=!this.fullscreen
      },
      handleCommand(command){
        if (command==='logout'){
          localStorage.removeItem('userName')
          this.$router.push('/')
        }
      }
    },
    computed: {
      userName(){
        return localStorage.getItem("userName")
      }
    }
  }
</script>

<style scoped>
.header{
  position: relative;
  background-color: #253041;
  box-sizing: border-box;
  width: 100%;
  height: 70px;
  font-size: 22px;
  color: #ffffff;
}
.collapse-btn{
  float: left;
  padding: 0 21px;
  cursor: pointer;
  line-height: 70px;
}
.logo{
  float: left;
  line-height: 70px;
}
.header-right{
  float: right;
  padding-right: 50px;
  display: flex;
  height: 70px;
  align-items: center;
}
.btn-fullscreen{
  transform: rotate(45deg);
  margin-right: 5px;
  font-size: 24px;
}
.user-avator{
  margin-left: 20px;
}
.user-avator img{
  display: block;
  width: 40px;
  height: 40px;
  border-radius: 50%;
}
.user-name{
  margin-left: 10px;
}
  .el-dropdown-link{
    color: #ffffff;
    cursor: pointer;
  }
</style>
